Hi,
Thanks for using the Events Calendar.
Here on the pre-sales forum, I’m afraid we do not provide technical support. I would ask that you take any technical support questions across to our wordpress.org forum – our staff scan it periodically and other community members may also be able to help out.
The Events Calendar
If you have purchased a plugin from us, please login and post in the premium forums for that plugin and we can help you out there:
https://theeventscalendar.com/support/forums/
Having said that this tends to happen if on the first event someone choose the end date as something far in the future. It will start creating a massive amount of large events.
You can delete series of recurring events by find the first one and click the delete series button.
Thanks again!